1. Field of the Invention
This invention relates generally to control devices, and more particularly to a temperature control device having illuminating means for determining the temperature at which the device is set.
2. Prior Art
It has been found that prior art temperature control devices are difficult to read and adjust. For instance, in the residential heating field control devices, which are usually temperature responsive, are often located in areas which are poorly lighted making it difficult for a person to determine the temperature at which the control device is set, and also to effect the desired setting.
Thermostatic control devices are well known in the art particularly those used to control the temperature of a residential unit. Both U.S. Pat. 3,251,549 to Hewitt, Jr. et al and U.S. Pat. No. 4,171,769 to Trimpey have thermostatically controlled temperature control devices which have an illuminating means associated therewith. Hewitt, Jr. et al provides a means for illuminating the complete dial; and Trimpey provides a light which is used as a night light apparatus and which also controls the heating system.
Color codes have been used in some electrical devices for example, U.S. Pat. No. 2,514,745 to Dalzell describes a color coded changeable scale electrical testing instrument; U.S. Pat. No. 2,582,024 to Finleyson describes a color coded heat setting and temperature indication device for use on a flatiron; U.S. Pat. No. 4,169,357 to Kelley describes a color coded device for use on a refrigerator and freezer monitoring device; and U.S. Pat. No. 3,621,811 to Hill, Jr. describes a color coded indicating condition controller.
None of the foregoing devices teach or suggest the invention described and claimed herein nor do they permit one to observe easily the temperature to which a temperature control device has been set, i.e. the predetermined temperature, from a distance by the mere observation of the color which is lit up on the temperature scale.